/* -*- mode: C -*-  */
/* 
   IGraph library.
   Copyright (C) 2006-2012  Gabor Csardi <csardi.gabor@gmail.com>
   334 Harvard st, Cambridge MA, 02139 USA
   
   This program is free software; you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
   the Free Software Foundation; either version 2 of the License, or
   (at your option) any later version.
   
   This program is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   GNU General Public License for more details.
   
   You should have received a copy of the GNU General Public License
   along with this program; if not, write to the Free Software
   Foundation, Inc.,  51 Franklin Street, Fifth Floor, Boston, MA 
   02110-1301 USA

*/

#include <igraph.h>

void igraph_vector_print(const igraph_vector_t *v) {
  long int i;
  for (i=0; i<igraph_vector_size(v); i++) {
    printf("%li ", (long int)VECTOR(*v)[i]);
  }
  printf("\n");
}

int main() {
  
  igraph_t g;
  const igraph_vector_t v=IGRAPH_VECTOR_NULL;
  igraph_real_t edges1[] = { 0,1, 1,2, 2,2, 2,3, 2,4, 3,4 };
  igraph_vector_t from, to;  
  igraph_es_t it;
  igraph_integer_t size;
  long int i;

  igraph_vector_view(&v, edges1, sizeof(edges1)/sizeof(igraph_real_t));

  /******************************************/
  /* Directed graph                         */
  /******************************************/
  
  igraph_create(&g, &v, 0, IGRAPH_DIRECTED);
  
  /* {0,1} -> {2,3}, result should be { 1->2 } */
  igraph_vector_init(&from, 2); VECTOR(from)[0]=0; VECTOR(from)[1]=1;
  igraph_vector_init(&to, 2);   VECTOR(to)  [0]=2; VECTOR(to)  [1]=3;
  igraph_es_fromto(&g, &it, IGRAPH_VS_VECTOR(&g, &from), 
		   IGRAPH_VS_VECTOR(&g, &to), IGRAPH_DIRECTED);
  igraph_vector_clear(&from); igraph_vector_clear(&to);
  igraph_es_size(&g, &it, &size);
  printf("%ld\n", (long)size);
  while (!igraph_es_end(&g, &it)) {
    igraph_vector_push_back(&from, igraph_es_from(&g, &it));
    igraph_vector_push_back(&to, igraph_es_to(&g, &it));
    igraph_es_next(&g, &it);
  }
  igraph_vector_sort(&from); igraph_vector_sort(&to);
  igraph_vector_print(&from); igraph_vector_print(&to);

  igraph_es_destroy(&it);

  igraph_vector_destroy(&from);
  igraph_vector_destroy(&to);
  
  return 0;
}
